Static air pressure values unknown so I believe every one will have difficulty making a good recommendation for you.

I would like to see your filter holder. I have never seen a installation with 2 1" filters.

My gut tells me 2 filters in series you might want to go down to Merv 2. So that the static air pressure is not to high for the unit.

 

Static air pressure values unknown so I believe every one will have difficulty making a good recommendation for you.

I would like to see your filter holder. I have never seen a installation with 2 1" filters.

My gut tells me 2 filters in series you might want to go down to Merv 2. So that the static air pressure is not to high for the unit.

So you're saying go ahead and stack the 2 filters merv2 or merv1 to make up for not using a merv5 filter. I'm not afraid to use a single or two just don't want to clog or burn up a Goodman ac unit as the regular pleated merv5 is what ive been using bur from the 90s when i stayed here my grandparents used the green filters I think in singles which didn't cause any problems. See photos below.

 

I don't understand your question. Use a merv 5 or 8. Merv 2 isn't good enough for ac, it's ok, but not great, for heating only.

If it's not a pleated filter just use a single 1" filter. If you get a pleated filter, the thicker you fit in your rack, the better.

 

I was saying unfortunately at lowes the regular merv5 singles were out of stock and needed filters immediately or a filter as the old merv5 was dirty. So I got the merv2 single cross thread in the last photo but in the 90s my grandparents always used the green threaded filters with no issues which looks to be the same type. The green ones advertise 4x more airflow but are merv1 so I'm thinking the merv2 are slightly better. The electric bill is already high from the HVAC unit in the summer. You're saying the green merv1 or merv2 are only for heater use? I don't see any reason in going over a merv5 but if the merv8 is better for the same price possibly just don't want to slowdown airflow causing excessive ac use or use a weak merv1-2 if it will end up clogging the ac or similar to using without a filter.

There's is 2 slots for 16x25x1 air filters.

 

It was my only option so get a merv5 asap? Here's the two slots and airflow resistance gets up to 3 times nearly less with the merv2-merv5.

Its been maybe 2 months there's the old merv5 I was using and needed some filters immediately or is that not as dirty as it possibly could be?

 

Probably there is a metal adaptor on each side of your filter rack that should slide out allowing you to use a 1” filter with the adaptors in and a 2” filter with the adaptors removed. Hard to tell from the pics but that’s a common filter rack setup at least at my supply houses and it looks like what you have. Probably not good to use two 1” filters in my opinion.

 

It's the standard Goodman HVAC unit from the 90s or older model. Why would you use merv2 with the heater and change to merv5 with ac? Ac is used from March to Nov maybe then in Texas heat it switches to December 60s-30s and 107+ degrees summer time.

This is strange theory. How many degrees is a Ac unit suppose to cool a house typically compared outside heat? Someone told me one time that automobile ac cooled it 10-14 degrees cooler then outside or may have been home ac I think when it's fully hot index.

 

https://filterking.com/air-filter-sizes/16x25x2

There are so many variables to answer your last question. Depends on in the inside and out side temps and how long the unit is running. A thumb measure would be 10-15 F after the unit is running for at least 5 minutes.

You measure the return air and then a supply vent compare the numbers with the same thermometer. The delta T (differential) is not measured from the outside air. If it is 130F outside the delta will probably be 10 or less.
AC's used to be made for an ambient of 88F. I believe it was raised to 92F. Which means as soon as the ambient goes over that number the unit starts losing BTU's in production. Every MFG has a table on this for their equipment.

Air filters are not put on units to clean the air in your home. They are to keep the equipment reasonably clean nothing more. If you want to filter air I suggest Conway. I have one and it works great, even in Arizona with a dog.

 

That isn't 2 slots, that's only 1 with angle to make hold it well. The bottom half is just dead space used by the brackets. Don't put a filter there.

Merv 5 is fine. Merv 8 will need to be changed sooner, but if it's all that's available, use it until you can find the merv 5s. A 1" merv8 is a bit restrictive so I wouldn't use it long unless you can actually check static pressure.

Your grandparents used a furnace that was designed with merv 3 filters in mind. They were very low static, low airflow furnaces designed to be as quiet as possible for the time, as it was compared to other silent types of heating. They couldn't handle anything more restrictive. It also wasn't a crazy idea to expect a home owner to pull the coil to clean it carefully without disturbing the lineset every year. That's just not the case anymore and we expect to have to keep the coil clean for the duration of it's life.

60-80% efficient furnaces only need a merv 3 anyways as you only need to protect the blower wheel. +85% efficient furnaces need a bit more protection but the wet coil of the ac need the most protection. Your grandparents probably only had a 50-60% efficient furnace. It appears you have an 80% but I can't be sure as your pictures cut it off.

 

the coils from back then likely had the fins spaced further apart so dirt was less of an issue.

 

A bit but not really significantly. I found plenty that were so matted they could be a carpet.

 

Stacking filters doesn't work.
Even 1" filters are layered so they install only one way because of that.
Stacking two one inch filters is redoing air flow and that is the last thing you want.
Either use one 1" or pull out the support angles and use one 2".

 

Stacking filters doesn't work.
Even 1" filters are layered so they install only one way because of that.
Stacking two one inch filters is redoing air flow and that is the last thing you want.
Either use one 1" or pull out the support angles and use one 2".

You can't remove the support angles. The filter would just fall down otherwise. They can be moved down but not removed. I'm not sure how far back the floor goes in this situation. Even though it would hold the filter somewhat, a 2" would restrict the air from flowing between the filter and floor causing additional restrictions. (you need the whole face, and in this case the floor is part of that return air duct.)

 

Was just trying to offer simple advice from my experience…. I don’t have the time to dig into your delta T’s and static pressures. But I do think you can maybe slide out two pieces of metal from the two outside edges inside of your filter rack and be able to use a 2” pleated filter possibly. It’s maybe worth two minutes of your time to see if those two side rails slide out…. If not I’m sorry for wasting your time.

 

Concrete temperatures

 

It's been two weeks with this type of filter. I don't want it to mess up the HVAC unit by clogging the cooling coils. Is it possible for a merv2 filter to clog the cooling coils sooner then a merv5 filter. It would make me nervous as haven't had to mess with the HVAC in 10 years other then the heater probe and drain clogged.

 

Coils would get dirtier faster with a merv 2.

Long term use something with better filtration.

 

What Merv are those , at one time , $1.89 USA 1" fiberglass at Wally or similar places ?

 

Yes. It will clog up the evap coil much sooner. Use merv5.

Well been using the merv2 filters for a few weeks now.

I seen the static pressure of the ac unit with no filter was 16" a cheap merv 1-2 24" and the filtrete 3m merv5 filter 43" so the 3m filters do have alot of resistance.

I seen someone tearing different brands same merv rating and some had less resistance then the others.

Of course im looking for the one with less resistance or restrictions but will still filter out without Getty the coils dirty.

Lowe's has the 3 pack 25x16x1 merv 5 filtrete 3m filters for 12.99$ and home Depot carries HDX box style merv8 filters 3 pack for 12.99$ the use to carry 3m filtrete same as Lowe's but recently changed to these since I last went shopping.

What anyone know if the merv8 HDX from home Depot has less resistance then the merv5 3m filtrete filters as it would help with airflow as well as filtering. I'm curious how the hdx merv8 operate but don't want something with a lot of resistance as it would cause the AC unit to run alot more then the other less restrictive filters.

Would anyone happen to know they usually say on the box the air flow resistance or restrictions of the hdx merv8 12.99$ 3 pack vs the 3m filtrete 3 pack for 12.99$ 25x16x1 or which one flows easier.

I was comparing the merv2 plain filter vs the merv5 filtrete and up higher in cfm the merv2 flows twice as much or less restrictive then the merv5 filter.

It's written on the actual filter chart itself so wouldn't know till having one in hand the merv8 HDX may be a better filter then the 3m filtrete with less resistance.

 

Merv 8 is a bit restrictive, so I would avoid it when using only 1" think filters.

3m generally are more restrictive than the competition, but usually not by that much. Resistance is determined by the actual media material AND surface area AND geometry AND air volume. So you can get different resistances between different filters manufacturers even assuming everything else is the same.

I hope that you meant to add a decimal in your numbers. 0.43 and 0.16"wc sounds way more valid than 16" wc. How exactly did you measure this?

Ah I was watching YouTube videos where he measured status pressure I think it's called between different filters with different merv5 ratings and brands. The filtrete 3m was more restrictive then some more expensive merv8 filters that measured in the low .30s area.

I'm not sure how you measure or what it's called status air pressure or vacuum? You'll have to excuse me I forgot some things since late 2012 or mid 2013 and have been tied up busy so I can't do my regular activities the last 10 years.

No filter was either .16, a mer 1-2 .24 and filtrete 3m merv5 .43 using the same AC unit with the same way of measuring a digital pressure reader or vacuum? He did use washable filters and multiple other filters that had high r merv rating were only .33 or less then filtrete anr some in the above .50s. That must be after the filter shows the ac unit would have to work harder with a more restrictive filter.

let me see if I can find it was a video I searched which filter flows best or causes restriction which would cause the AC unit to run harder.

 

Merv 8 is a bit restrictive, so I would avoid it when using only 1" think filters.

3m generally are more restrictive than the competition, but usually not by that much. Resistance is determined by the actual media material AND surface area AND geometry AND air volume. So you can get different resistances between different filters manufacturers even assuming everything else is the same.

I hope that you meant to add a decimal in your numbers. 0.43 and 0.16"wc sounds way more valid than 16" wc. How exactly did you measure this?

Hey I think this is it was a few weeks ago watch this is what I was talking about. Tests different filters with flow ratings and their tests both clean and dirty and their airflow test. I didn't see the 3 pack 11.99$ hdx home Depot filters recently switched from same lowes 3m filtrete merv5 to merv8 hdx box style encased which possiblly aren't as reagrictive or hard on the ac unit. With the plain white merv2 filters I bought weeks ago was using 3m merv5 since 2019 2018 but my grandparents always used the green crossthreaded filters in the 90s probably the cheaper ones. I noticed the ac unit turns off or takes a break more often with these merv2.

 

I didn't like his test setup, but the static pressure comparison is fine. The static pressure numbers themselves mean nothing to you without knowing the volume of air. Maybe he said it, I did skim the video but pressure drop isn't linear. The good brands publish pressure drop charts for their filters.

The point being, higher resistance is harder on your blower motor.

Yeah it's a Goodman HVAC unit from the 90s maybe older with the 25x16x1 filters.

How do you clean the coils yourself on one of these? The front cover just above the drainage pan on top of unit?

The air flow resistance chart per more cfm flow is on the filter itself I don't think anywhere on the package I was only able to see it on the edge of the filter itself on the two different ones I bought.

I wonder how good the Flanders are the green cross thread they advertise 4x airflow of the other filters and pack of 4 is 6$ at Walmart.